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Discussion Starter · #1 ·
Just finished putting on a jockey shift kit from J&P, and am totally unhappy with it. I am unhappy due to the placement of the shift handle. The actual kit (foot control and cable routing) is actually an improvement over the last setup I used.

My plan was to ride it with the jockey shifter for awhile and fabricate a tank side shift for it later (free on the side with no gate). However, considering my displeasure with the current setup (I know I could get a new shift handle manufactured), I plan on just going ahead with the tank side shift.

Which brings me to my question. I have a tank side shift kit (police) that says it can be used on ratchet top or rotary type transmissions. Could someone explain to me what the difference is? I've already checked the kit out, and can make it work with very little effort on my application, so this isn't a "will this work on my bike" question, but more of a knowledge expanding question.

If you could explain the basic differences between the two trannys I would be most greatful.

Cheers
 

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Ratchet top has a drum with an axis running left to right on the bike, the drum has slots in it which engage the shifter forks and move the gears. A Rotary top has an axis that runs from top to bottom (seat to the ground I guess you could say) The rotary disc has slots in it that engage the shift forks. They switched to rotary in late 79.

Ok technically the ratchet isn't a drum but rather a round casting, but it used to be a drum back in the day.

Jockey shifts could be cool I guess. I have original tank shift on one of mine and I can't imagine it placed in an awkward position. The factory location is very natural. Use a rocker clutch not a suicide if you can help it.
 

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GoGo said:
Just finished putting on a jockey shift kit from J&P, and am totally unhappy with it. I am unhappy due to the placement of the shift handle. The actual kit (foot control and cable routing) is actually an improvement over the last setup I used.

My plan was to ride it with the jockey shifter for awhile and fabricate a tank side shift for it later (free on the side with no gate). However, considering my displeasure with the current setup (I know I could get a new shift handle manufactured), I plan on just going ahead with the tank side shift.

Which brings me to my question. I have a tank side shift kit (police) that says it can be used on ratchet top or rotary type transmissions. Could someone explain to me what the difference is? I've already checked the kit out, and can make it work with very little effort on my application, so this isn't a "will this work on my bike" question, but more of a knowledge expanding question.

If you could explain the basic differences between the two trannys I would be most greatful.

Cheers
I'll give it a try alhtough someone may know a lot more about this topic than I. I first saw a ratchet top back in the 50's so it's the very first design that HD used for a foot shift. I bought a setup with a Mouse Trap and clutch lever and cable from a guy that didn't lke it and installed in on my 1950 Panhead. The rotary top or "cowpie" transmission didn't come out until much later, in the Shovelhead era I believe.

That said, I think the ratchet top shifter is much easier shifting and perhaps even more positive and probably less travel to shift. I have the Cowpie type in my 1982 FXS and, while it's dependable, the shifter moves rather stiffly and somewhat farther to make a shift compared to the ratchet top. I think the guts of the trannys are quite similar but the tops are the main difference, although not interchangeable. The mainshafts are different lengths also.

If I were going to use a jockey shift, I would certainly opt for the ratchet top due to the basically smoother operation. I know that they are quite a bit more popular with custom bike builders.

I'm not sure what you mean by a tank shift kit. The original tank shifts for the OHV twins were for the hand shift transmission top. Those came out in 1936 and went all the way up to whenever HD quit doing hand shifts. Flatheads of that era had the same transmission...They were linear in operation and went from low to fourth in a row, although some were three and reverse. The 1936 to 1946 had low gear towards the front of the gate and 1947-on to the end had low gear to rear of the shifter gate. The ratchet tops were built to interchange with the hand shift gear box case.

Hope this helps.
 

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Discussion Starter · #4 ·
Thanks for the info.

As far as the tank side shift is concerned, the linkage mount, bolts on to the left down tube, and I run the shift rod linkage from the handle pivot to the tranny shift arm (behind the primary).

I've used this setup before, but had the mount custom made. It was far cheaper for me to get the complete after-market setup and adapt it to my application (5 Speed Evo).

Whenever I get "motivated" I can post a pic of the setup.

Cheers
 
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